1. Field of the Invention
The present invention relates to a power tool and, in particular, to a power tool having a conventional body portion and provided with a plurality of interchangeable tool heads.
2. Description of the Related Art
As a result of considerable developments within the field of power tools and the increased demand of the DWY market, the number of different types of power tool available to the consumer has risen considerably in the past decade. In particular even the most reluctant of DIY enthusiasts will own a power drill and jigsaw, whilst their more enthusiastic counterparts will also require electric sanders, power files, nibblers and other specialised power tools having dedicated purpose. Whilst this considerable array of power tools is often found to be useful, owning such a large number is both expensive and requires a considerable amount of storage space. In addition, having one specialised tool to perform each job often results in significant under-utilage of such a tool which are, generally, all operated by similar motors. Still further, many of todays power tools are "cordless", being battery powered by rechargeable batteries, often requiring the user to change the battery pack when changing dedicated tools, or have several ready-charged batteries available for different tools. These current solutions are cumbersome or expensive respectively.
Attempts have been made to improve utilage of such power tools and to provide solutions to the above problems by the inclusion of attachments for a conventional drill, whereby the drill chuck is used to engage a drive mechanism of a reciprocating saw blade, an example of which is seen in U.S. Pat. No. 1,808,228. Another example of a multi functional tool shown in German Gebrauchsmuster 9010138 which shows a conventional drill body having a plurality of drill heads which operate at different speeds dependent on the gear reduction mechanism incorporated in those heads. However, the drawbacks of systems of this type is that where a drill chuck is used to operate a drive mechanism for a reciprocating saw, considerable energy is lost in the conversion mechanism of firstly driving a drill chuck which then drives the saw mechanism. Alternatively, where the tool incorporates interchangeable drill heads the variety of functions are somewhat limited to altering the speed of drilling.